This research will seek to develop an immunologic basis for the selection of GTF enzymes from Streptococcus mutans which will induce protection against dental caries in rodents caused by commonly encountered serotypes of this microorganism. Procedures will be performed, primarily in rats, to delineate both immunologic parameters of the secretory (esp. salivary) immune responses and the function of these salivary immune responses in protecting the animals from experimentally induced dental caries. Animals will be immunized with crude and defined enzyme antigens from S. mutans and the induction of antibody will be assessed by functional inhibition and radioactive GTF binding assays. The parameters of the secretory immune response to be studied include: relative affinity, relative avidity, maturation, duration, anamnesis, priming, and T-cell dependence of secretory antibody. Factors influencing the kinetics, anamnesis, and priming of immunocompetent cells in the salivary glands will also be investigated. Relative affinity and avidity of secretory antibody will be determined using the haptenated bacteriophage neutralization inhibition technique. Antibody activity of different Ig classes will be determined by sensitive hapten binding techniques. A combined immunofluorescence technique will be used to detect antibody-forming cells in salivary glands. The antigen preparations and immunization protocols will be integrated to develop conditions which might be eventually feasible for use in humans.